Desk lamp structure



May 19, 1964 Filed 001.. 2, 1961 J. MONROE DESK LAMP STRUCTURE 2Sheets-Sheet 1 INVZNTOR. JAY MON ROE BY? I May 19, 1964 .1. MONROE DESKLAMP STRUCTURE 2 SheetsSheet 2 Filed Oct. 2, 1961 INVENTOR ATTORNEYUnited States Patent Ofi ice 3,133,703 DESK LAMP STRUCTURE Jay Monroe,Flushing, N.Y., assignor to Tensor Electric Development Co., Inc.,Brooklyn, N.Y., a corporation of New York Filed Oct. 2, 1961, Ser. No.142,751 1 Claim. (Cl. 240-2) This invention relates to a desk lamp and,in particular, the invention concerns the use of a telephone jack andmating plug connector structure adapted to serve as an electricalconnector swivel connection and structural support.

This application is a continuation-in-part of my copending applicationSerial No. 51,752 for Variable Illumination Lamp, filed August 24, 1960.

It is a principal object of the instant invention to employ a telephonejack and telephone plug structure in a desk lamp stem, wherein thetelephone jack is attached to the lamp base such that upon mating thejack and plug, the connector structure serves the triple purpose ofelectrical connector, swivel connection means and also provides thestructural support for maintaining the lamp stem structure upright withrespect to the lamp base.

Further objects and advantages will become apparent from the followingdescription of the invention taken in conjunction with the figures, inwhich:

FIG. 1 is a perspective view of the lamp showing the means for swivelrotation of the lamp;

FIG. 2 is a Wiring diagram of the lamp showing the six selector contactpoint switch of FIG. 1, and the means for controlling uniformly thevoltage impressed across the light bulb from a source of fluctuatingline voltage;

FIG. 3 is a modification, showing a wiring diagram for effecting auniform voltage on the lamp bulb at all selected contact points of theselector switch;

FIG. 4 is an exploded view in perspective partly in section and cut-awayillustrating the connector structure; and

FIG. 5 is a vertical view in section of the mated connector structure ofthe invention.

In the operation of a desk lamp for doing precision work, for example,in the jewelers trade, or for camera assembly work or assembly andinspecting intricate radio and television apparatus, etc., it isnecessary at certain times to have extreme brightness for short timeintervals. At other and more normal times a conventional light intensityis desired. According to the illustrated embodiment, the highintensities are obtained by operating the lamp for short periods atvoltages above its normally used voltage. Use of the lamp at the highervoltages of course shortens the lamp life, but the gained time intervalsof intense illumination are often more desirable than longer life at thelesser intensities. It has been learned that at the high intensitiesWhere the bulb is burned at 3,133,703 Patented May 19., 1964 footcandles at the same distance. In this instance, the

' number one contact point may be set for 13 foot candles,

the number two contact for 43 foot candles, the number three contact for80 foot candles and the number four contact for 120 foot candles, allreadings being at a distance of twelve inches. The illustratedembodiment uses a plurality of thermistors in the circuit. One of thethermistors is used to prevent changes in the over voltage due to surgesof voltage current when the lamp is first turned on and the other isused to regulate line voltage fluctuations after the lamp is turned on.

As shown in FIG. 1, the desk lamp consists of a base 11, preferably ofsheet steel and having a flat top wall 12. A plug-in swivel contact base13 is disposed substantially in the center of the top wall 12 and aremovable co-acting swivel contact jack 14 is plugged into base 13 toeffect electrical contact with selective rotation of rod 15 and lamp 10throughout 360 degrees.

Base 11 is provided with a conventional wall plug 21 and with aconventional on-off switch 16 to energize the desk lamp and with arotary switch 17 to select the six difierent light intensities describedabove.

As shown in FIGS. 1 and 2, switch 17 is provided with a finger knob 17Xand a spring loaded depressable pin 18 is disposed between contactpoints four and five to separate the high intensities of short life,namely contact points five and six, from the contact points one to fourof relatively low intensities and therefore longer life.

Thus, finger knob 17X upon hitting stop pin 18 reminds the operator ofthe knob being at the threshold of high light intensity and also itprevents accidental turning on of the said high intensity illuminations.

Pin 18 is disposed in an aperture of the top wall 12 with a top flangedisposed above said base top wall 12, and a bottom flange disposed belowsaid top wall 12. Thus, the rod is captively held in base wall 12 and iscontinuously urged outwardly thereof by a coil spring 19. Thus, topermit switch knob 17X to pass beyond pin 18, the pin is depressedagainst spring 19 toward Wall 12 to permit the knob to pass over it.

As shown in FIG. 1, the numerals 1 to 6 on the top wall are indicativeof the contact points and not the points themselves which are locatedwithin base 11. To add greater usefulness to the desk lamp, an auxiliaryoutlet plug 20 is provided.

Turning now to the wiring diagram, FIG. 2, wherein the ground isdesignated by a conventional symbol, the electrical power is suppliedthrough line plug 21 to a multi-stage transformer 22 which provides atits secondary winding the six contacts for the six pre-selected voltagesI described above.

voltages above those normal for the bulb, the bulb filament will beburned out in a shorter time where fluctuating line voltage isencountered than is the case where the line voltage is held constantacross the bulb filament during high intensity or overrated voltage useof the bulb. To maintain a constant voltage during such high intensityuse where the bulb life is normally relatively short, this inventionpreferably uses thermistors and thereby increases the life of the bulb.

Turning now to the drawing, there is shown an electric desk lamp adaptedfor six selective light intensities of the light bulb 10. Of course, thenumber of contact points may be more than six or less than six asdesired. In the above example where six contact points are provided forsix different levels of intensity of illumination, the number sixcontact point may be for 290 foot candles at twelve inches While thenumber five contact point may be for 190 Regulation of the voltage tolamp 10 may be done in two ways, for example, it may be done bydisposing regulation means in the fifth and sixth position of thesecondary (FIG. 2) or the regulation may be done by placing the voltageregulation means in the primary circuit (FIG. 3).

Turning now to FIG. 2, when selector knob 17X is disposed in position 5,the secondary circuit consists of transformer 22 in series withthermistor 23, and resistor 24 and lamp 10 is shunted by thermistor 25in series with resistor 26. If the line voltage at plug 21 increases,the current increases causing the resistance of thermistor 25 todecrease. This in turn causes a larger percentage of the input voltageto appear across thermistor 23 and the conventional resistance 24. Thevalues of elements 24, 25 and 26 are chosen so that the change inresistance of the thermistor is exactly the correct amount to cause thelamp voltage to remain uniform or constant at the desired preselectedvalue.

Thermistor 23 functions as a surge protector for lamp 10. When lamp 10is first turned on, thermistor 23 has a fairly high resistance whichlimits the initial voltage across lamp 10, However, as thermistor 23heats up due to its current, its resistance decreases to a small valueand after a short time interval the full voltage appears across the lamp10 filament.

For contact position number 6, the voltage regulation works in a manneridentical to that described for contact position number described above.The numerals 23X, 24X, 25X and 26X refer to the equivalent elements 23,24, 25 and 26.

Turning to FIG. 3, the voltage regulation is brought about as in thecase for contact point number 5. In this case, thermistor 23Y functionsas a surge protector for lamp 10. As an example of the use of lamp forhigh intensity illumination, the voltage at contact position number 5 isheld uniform at 8.3 volts and the voltage at contact point number 6 isheld uniform at 9.6 volts.

As seen hereinbefore, telephone plug 14 at the end of lamp rod isplugged into telephone jack 13 fastened to lamp base 11. In accordancewith the invention, these connector components serve three basicfunctions in the operation of the lamp structure. First, thesecomponents serve as means for connecting electrical power to lamp 10, asdepicted schematically in FIG. 2. In addition to this normal function,the mated connector components 13, 14 also serve as a structural supportfor holding rod 15 and the lamp structure at its upper end in uprightcondition during use of the lamp. Thirdly, the mated jack and plugstructure provides a swivel connection to allow rod 15 to swivel aboutthe vertical axis, as shown in FIG. 1. The jack spring grip pressureagainst a telephone plug contact tip provides sufiicient friction tohold rod 15 and the lamp carried by it in a desired and set positionabout the vertical axis after rod 15 is turned to such position.

FIGS. 4 and 5 illustrate the components of connector jack 13 andconnector plug 14 for accomplishing the foregoing results. Telephoneplug 14 has a first conductive member 30 provided with a pointed headfollowed by a restricted neck 31 defining the contact tip 32. Member 30is insulated by an insulator 33 from a second conductive member 34mounted over insulator 33. Member 34 has an outer cylindrical sleeve andalso has a flange 35 and a threaded upper section 36 for holding anouter conductive jacket 37, which jacket 37 is lined with an insulator38. A lamp socket for lamp 10 is connected by Wires 39, 40 to individualones of terminals 41, 42, wherein one terminal 41 is connected toconductive member 34 and the other terminal 42 is connected toconductive member 30.

Telephone jack 13 has a hollow threaded conductive nipple 43 fastened tothe outer end of conductive upper arm 44, which arm 44 at such end isclamped by a nut 45 to the top face 12 of base 11, whereby only nipple43 extends up from base face 12. The remainder of jack 13 is in theinterior of base 11. The inner end of arm 44 has a conductive lug 46provided with a terminal 47 which in accordance with FIG. 2 is connectedto ground. A second and resilient arm 48 of conductive material isfastened to lug 46, but arm 48 is electrically insulated therefrom by aninsulator 49. Second arm 48 has a terminal 50 for connecting same toselector 17X, as depicted in FIG. 2. Arm 48 extends below arm 44 and hasa V-shaped probe 51 at its outer end. Upon mating of plug 14 in jack 13,V-shaped probe 51 snaps into engagement with restricted neck 31 of plugtip 32. This engagement is maintained by the spring action of arm 48 andprovides sufiicient friction to hold telephone jack 13 and the attachedrod and lamp structure 15, 10 fixed in position until rod 15 is manuallyturned about its vertical axis to allow swivel action to any positionover the 360 degree range. In addition, the combination of the springgrip probe 51 against contact tip 32 while cylindrical section 34 ofplug extends through jack nipple 43 provides the mechanical support forrigidly holding lamp 10 and rod 15 upright for use. When the connectormembers 13, 14 are mated, plug member 34 makes electrical contact withnipple 43 to ground one side of lamp 10 connected thereto, whereas tip32 is connected to spring arm 48 to connect the other side of lamp 10 toone of the transformer taps 1,2, 56.

It is intended that all matter contained in the above description orshown in the accompanying drawings shall be interpreted as illustrativeand not in a limiting sense.

What is claimed is:

A desk lamp comprising, a base for supporting a desk lamp with respectto a supporting surface, said base having a top surface, a telephonejack connector mounted in said base and having a hollow conductivesleeve opened at its outer end, the open end of said jack sleeve beingexposed with respect to said top surface to receive a telephone plugconnector, a rigid and axial lamp stem and lamp bulb means attached atone end thereof, a telephone plug connector at the other end of saidstem and having a substantially tubular conductive member for insertableand swivel connection in said jack sleeve, said telephone plug having acontact tip at its end electrically insulated from the remainder of itssubstantially tubular member thereof, electrical wire means forconductively connecting one side of said bulb to said contact tip andthe other side of said bulb to the substantially tubular member of saidplug connector, said jack connector also including grip springconductive means in the interior of said base for slidaoly snapping oversaid plug contact tip upon telescopic insertion of said plug into saidjack, said grip spring means being electrically insulated from said jacksleeve, and means in said base for conductively connecting an electricalvoltage potential between said jack spring means and said jack sleevefor illuminating said bulb, said telephone plug member being inconductive and also swivel engagement with said jack sleeve upon matingof said connector members, said jack also serving as a structuralsupport for holding said stem and bulb attached thereto relativelyupright with respect to said base when said connector members are matedand also permitting rotation of said stem and lamp about the axis of themated connector members to any selected position, said spring meansnormally providing friction for holding said stem and lamp in desiredposition about said axis.

References Cited in the file of this patent UNITED STATES PATENTS2,151,897 Chaplin Mar. 28, 1939

